Thanks to everyone who tried to help with my original question about pre-preg material dielectrics. As it turns out I used the wrong term. What I meant was, I would like to get the dielectric constants for the materials commonly used to make PCBs. These include FR4, Tetrafunctional FR4, G10, GTEK, Polyimide, Cyanate Ester, Teflon and the new material from GORE, what ever it is called. Would it be possible to get the ranges as well, since I know that the dielectrics are not necessarily constant. Assume that testing is out of the question. Since I am at it. Have I missed any materials? I know that there are some new ones that I may not be aware of. Gary ================================================== 0000,0000,ffffGary Griffin Engineering Manager Phone (408) 501-7156 Fax (408) 437-1976 Pager 1-800-759-7243 Pin: 145-1886 Alpha pager email griffin_p or [log in to unmask] SABER group Interface Products ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################